Milk somatic cell counts(SCC),total protein content,nonprotein nitrogen(NPN) and milk urea nitrogen(MUN) content were determined.

• 对乳牛随机采样,共采样16次,得到530个有效乳样;检测乳样中体细胞数(SCC)、总蛋白、非蛋白氮(NPN)、尿素氮(MUN)含量。